docs: def get_depth_distribution(self, depth_bins, normalisation=False,
                                 bootstrap=None):
          '''
          Gets the depth distribution of the earthquake catalogue to return a
          single histogram. Depths may be normalised. If uncertainties are found
          in the catalogue the distrbution may be bootstrap sampled
  
          :param numpy.ndarray depth_bins:
               getBin edges for the depths
  
          :param bool normalisation:
              Choose to normalise the results such that the total contributions
              sum to 1.0 (True) or not (False)
  
          :param int bootstrap:
              Number of bootstrap samples
  
          :returns:
              Histogram of depth values
  
          '''
          if len(self.data['depth']) == 0:
              # If depth information is missing
              raise ValueError('Depths missing in catalogue')
  
          if len(self.data['depthError']) == 0:
              self.data['depthError'] = np.zeros(self.get_number_events(),
                                                 dtype=float)
  
          return bootstrap_histogram_1D(self.data['depth'],
                                        depth_bins,
                                        self.data['depthError'],
                                        normalisation=normalisation,
                                        number_bootstraps=bootstrap,
                                        boundaries=(0., None))